eDrug Update - April 2015

Human papillomavirus (HPV) continues to be a clinical burden. Annually, it causes about 26,800 of the approximately 33,000 new cases of cancer associated with parts of the body where HPV is often found. HPV has been attributed to having a causal role in more than 90% of anal and cervical cancers, about 70% of vaginal and vulvar cancers, and more than 60% of penile cancers. Additionally, though most head and neck cancers are caused by tobacco and alcohol use, recent studies have suggested that about 70% of oropharyngeal cancers (cancers of the back of the throat, including the base of the tongue and tonsils) may be linked to HPV. A combination of tobacco, alcohol, and HPV may be the cause for many of these cases. Research is still being done to understand how and to what extent HPV causes these cancers. The most common HPV-associated cancer among women is cervical cancer; for men, oropharyngeal cancers are the most common.

In most instances, HPV resolves on its own in under two years, without causing more severe health problems. The body’s natural immune response is believed to be able to eliminate HPV, but there is no conclusive explanation for why is it successful in most, but not all, cases. When the immune system is not able to fight off HPV and it stays in the body for many years, the risk exists for HPV infection to lead to cancer.

Vaccines are available that can protect against the types of HPV that most often cause cervical, vaginal, vulvar, and anal precancers and cancers, as well as the types of HPV that cause most genital warts. Currently, there are three HPV vaccines, Cervarix, Gardasil, and Gardasil 9, given as a series of three shots over six months to protect against HPV infection and the health problems that it can cause. Any of these HPV vaccines can be given for the prevention of cervical cancer in girls and young women.

Gardasil and Gardasil 9 also protect against genital warts and anal cancer in both females and males. Boys should get one of these HPV vaccines for prevention of anal cancer and genital warts. Either of these vaccines is also beneficial for girls as prevention of cervical cancer, vulvar cancer, vaginal cancer, anal cancer, and genital warts.

Prevention of precancers or cancers in other areas of the body, such as the penis or oropharynx, has not yet been demonstrated; however, HPV vaccines do offer protection against the HPV types most often found in those cancers. While vaccine coverage is increasing, cervical cancer can still be prevented or found early through regular screening and follow-up treatment, so these measures are recommended for women.

Who Should Get the Vaccine?

It is recommended that preteen girls and boys receive HPV vaccination at age 11 or 12 years, since the best protection is possible in those who receive all three vaccine doses and have time to develop an immune response before being sexually active with another person.

The vaccine is also recommended for teenage boys and girls who did not start or finish the vaccine series when they were younger.

Young women are permitted to receive the HPV vaccine through age 26, and young men can do so through age 21.

Men who have sex with men, and men with compromised immune systems (including HIV), may be vaccinated through age 26, if they did not receive an HPV vaccine when they were younger.

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